The European Community’s program on the completion of the internal market has, as the primary objective for medical devices, to assure community-wide free circulation of products. The only means to establish such free circulation, in view of quite divergent national systems, regulations governing medical devices, and existing trade barriers, was to adopt legislation for the community, by which the health and safety of patients, users, and third persons would be ensured through a harmonized set of device-related protection requirements. Devices meeting the requirements and sold to members of the community are identied by means of a CE mark.